Fecal Calprotectin Level of 15 μg/g: Interpretation and Management
What This Result Means
A fecal calprotectin level of 15 μg/g is well below the threshold for intestinal inflammation and effectively rules out inflammatory bowel disease (IBD) with high confidence. 1, 2
This value is far below the 50 μg/g cutoff that has 90.6% sensitivity for detecting endoscopically active disease, making IBD highly unlikely. 1, 2 The American Gastroenterological Association specifies that calprotectin <150 μg/g reliably rules out active inflammation in ulcerative colitis, and your value of 15 μg/g is nearly 10-fold lower than this threshold. 1, 2
Clinical Significance
No endoscopic evaluation is needed given this extremely low calprotectin level, even if gastrointestinal symptoms are present. 2
This result has high negative predictive value for IBD, meaning it is excellent for ruling out inflammatory bowel disease in symptomatic patients. 1, 2
If symptoms are present (such as intermittent loose stools, abdominal discomfort, or bloating), they are most consistent with irritable bowel syndrome (IBS) rather than inflammatory disease. 2
Management Approach
If Symptomatic:
Implement a low FODMAP diet as first-line dietary management for functional gastrointestinal symptoms, with careful attention to nutritional adequacy. 2
Recommend psychological therapies including cognitive behavioral therapy, hypnotherapy, or mindfulness therapy, as these are evidence-based treatments for IBS symptoms triggered by stress. 2
Encourage physical exercise as it benefits functional gastrointestinal symptoms. 2
Consider antispasmodics for abdominal pain or hypomotility agents/bile-acid sequestrants for chronic diarrhea if dietary and stress management are insufficient. 2
If Asymptomatic:
No further action is required. 2
Serial monitoring at 3-6 month intervals is not necessary given this extremely low baseline value. 2
When to Reconsider Testing
Repeat fecal calprotectin measurement is warranted only if:
Symptoms worsen significantly or change character 2
Symptoms fail to respond to IBS-directed management 2
New alarm features develop, such as rectal bleeding, unintentional weight loss, nocturnal symptoms, or family history of colorectal cancer or IBD—these would require endoscopic assessment regardless of calprotectin level. 2
Important Context
Calprotectin is a neutrophil-derived protein that serves as a surrogate marker of gastrointestinal inflammation, with fecal concentrations approximately six times higher than plasma levels. 3
The absence of alarm features combined with a normal calprotectin level strongly supports a functional diagnosis rather than organic disease. 2